PROJECT SUMMARY Early-childhood educators (ECEs) often use detrimental feeding practices and are slow to implement positive feeding practices. This is a significant problem because eleven million children in childcare settings in the US31 may eat more than two-thirds of their daily diets with ECEs, and dietary habits established in childhood persist into adulthood. Nevertheless, few studies have aimed to understand and change ECEs' feeding practices. Our long-term goal is to improve diet quality and related health outcomes of children by intervening with an innovative approach to improve ECE feeding practices. My K01 research project uses principles of Implementation Science (IS) to increase ECE adoption of evidence-based nutrition promotion practices with the WISE (Together, We Inspire Smart Eating) intervention. The K01 project, however, does not explicitly attempt to decrease routinized, detrimental practices. This gap needs to be addressed because implementation (i.e., adding new, evidence-based practices) and de- implementation (i.e., stopping low-value or harmful practices) are distinct processes that require unique strategies. The overarching hypothesis is that adoption of evidence-based feeding strategies at mealtimes will be improved when combined with active strategies to remove detrimental practices. To test our hypothesis, we propose the following specific aims that will apply emerging concepts in (IS). Specific Aim 1. Develop a de-implementation strategy for detrimental feeding practices. Building on the design of my K01 study, we will use evidence-based quality improvement (EBQI) sessions to engage stakeholders in developing a de-implementation strategy for detrimental feeding practices. Specific Aim 2. Investigate the effects of the de-implementation strategy in a proof-of-principle study. The de-implementation strategy (developed in Aim 1) will be evaluated in 2 partnering childcare agencies using a pre-post, within-site design. We will interview educators throughout the school year to assess the feasibility and acceptability of the intervention, and we will investigate its effects on the use of detrimental and evidence-based feeding practices by teachers and impacts on child BMI and diet. The proposed R03 activities will align with the K01 to provide fundamental insights into processes related to de-implementation efforts in a community setting. All children in childcare settings eat meals with ECEs, regardless of the individual center's participation in other nutrition-promotion interventions in the classroom. Therefore, focusing on childcare meals is consistent with the emphasis of the NIDDK Obesity Prevention and Treatment Research Area on preventing obesity development in high-risk populations. These results will contribute to future uptake and sustainability of mealtime interventions to improve diets of young children.